Elm or sycamore (4)
I believe the answer is:
tree
This clue is a double definition.
'elm' is the first definition.
(I've seen this in another clue)
'sycamore' is the second definition.
(thesaurus)
(Other definitions for tree that I've seen before include "famous actor" , "''I think that I shall never see / A poem lovely as a ...'' (Kilmer)" , "Tall, woody plant" , "Plane, e.g." , "Eg, cypress" .)